HOW-TO: Pair and Connect your Logitech Harmony Home Hub with Extender with a GE Smart Switch - YouTube
Logitech Harmony RF Wireless Extender
Amazon.com: Harmony IR Adapters, Ancable 2-Pack 2.5mm Mono Plug to 3.5mm Mono Jack Connector for Logitech Harmony Hub and IR Blaster, IR Emitter Extenders, IR Repeaters, IR Receivers : Electronics
Harmony® RF Wireless Extender Extends the range of select Harmony remotes at Crutchfield